Organosilylamines reaction between organosilylamine and a silanol-containing organosilicon material

ABSTRACT

Bis-organoaminosilalkylenes and bis-organoaminosilarylenes are used to couple silanol stopped fluids to form gums. The process is fast and the molecular weights of the gums formed are very high with no deleterious byproduct formed during the gum formation. The gums which contain recurring silarylene units are used to make silicone rubber. The rubbers formed have the radiation resistance, hydrolytic stability and high temperature properties which are known characteristics of polysiloxanes containing silarylene groups.

United States Patent Goossens [54] ORGANOSILYLAMINES REACTION BETWEENORGANOSILYLAMINE AND A SILANOL-CONTAINING ORGANOSILICON MATERIAL [52]US. Cl ..260/46.5 G, 260/37 SB, 260/46.5 E, 260/465 P, 260/47 R,260/4482 N, 260/825 [51] Int. Cl. ..C08f ll/04 [58] Field of Search..260/46.5 E, 46.5 G, 46.5 P, 260/825 R, 47 R, 448.2 N

[56] References Cited UNITED STATES PATENTS 3,305,525 Goossens..260/46.5

[ 51 July4, 1972 3,032,528 5/1962 Nitzsche et al. ..260/46.5 3,219,72611/1965 Bailey et al. ..260/825 2,562,000 7/1951 Sveda ....260/46.53,202,634 8/1965 Merker ....260/46.5 3,338,870 8/1967 Nitzsche et a1.....260/46.5 3,135,777 6/1964 Nielson ..260/448.2 3,398,175 8/1968Leitheiser ..260/448.2

Primary ExaminerDonald E. Czaja Assistant Examiner-M. l. MarquisAtt0mey-William A. Teoli, Robert S. Friedman, Frank L. Neuhauser, OscarB. Waddell and Melvin M. Goldenberg [57] ABSTRACTBis-organoaminosilalkylenes and bis-organoaminosilarylenes are used tocouple silanol stopped fluids to form gums. The process is fast and themolecular weights of the gums formed are very high with no deleteriousbyproduct formed during the gum formation. The gums which containrecurring silarylene units are used to make silicone rubber. The rubbersformed have the radiation resistance, hydrolytic stability and hightemperature properties which are known characteristics of polysiloxanescontaining silarylene groups.

3 Claims, No Drawings ORGANOSILYLAMINFS REACTION BETWEENORGANOSILYLAMINE AND A SILANOL-CONTAINING ORGANOSILICON MATERIAL Thisapplication is a division of copending application Ser. No. 603,115,filed Dec. 20, 1966- now U.S. Pat. No. 3,497,539.

The present invention relates to certain organosilylamines and to theemployment of these materials in combination with silanol containingorganosilicon materials to provide for the production of highermolecular weight reaction products.

The organosilylamines included by the present invention are shown by theformula,

where Y is a monovalent amino radical selected from NZZ and aheterocyclic amino radical, where Z is selected from alkyl radicals andZ is selected from hydrogen and alkyl radicals, R is selected frommonovalent hydrocarbon radicals, and halogenated monovalent hydrocarbonradicals, R is a divalent radical selected from alkylene radicals,arylene radicals, alkylenearylenealkylene radicals, alkyleneoxyalkyleneradicals, alkyleneoxyarylene radicals, aryleneoxyarylene radicals, andR"TR" radicals, where R" is selected from alkylene and arylene radicals,T is selected from is selected from hydrogen and R radicals.

Radicals included by R of Fonnula (l) are for example, alkyl radicals,such as methyl, ethyl, propyl, butyl, hexyl, heptyl, octyl, etc. Arylradicals and haloaryl radicals such as phenyl, xylyl, tolyl,chlorophenyl, etc., aralkyl radicals such as phenylethyl, benzyl, etc.,alkenyl radicals and cycloalkenyl radicals such as vinyl, allyl,cyclohexenyl, cycloheptenyl, etc.; alkynyl radicals such as ethynyl,l-propynyl, etc. Radicals in cluded by R are for example, alkyleneradicals, such as methylene, ethylene, trimethylene, tetramethylene,etc.; arylene radicals such as phenylene, tolylene, xylylene,naphthylene, etc.; alkyleneoxyalkylene radicals such asethyleneoxyethylene, ethyleneoxyu'imethylene, etc., alkyleneoxyarylenesuch as tetramethyleneoxyphenylene, dimethyleneoxyxylyene, etc.;aryleneoxyarylene such as phenyleneoxyphenylene, phenyleneoxytolylene,etc. In addition R' canberadicalssuchas any two or more of theaforementioned radicab.

The organosilylaminesofFormulaU) can be made byeffecting contact attemperature in the range of between 30 to 180' C, between an aliphaticor heterocyclic amine and halosilylorgano compounds of the formula,

2 R R XSi R SiX whereRandR'aredefinedabove,andXisahalogenrach'cal, forexample, cbloro, bromo, fluoro, etc. Solvents which can be utilized tofacilitate the formation of products and separation of amine salts arefor example, hexane, toluene, tetralin, etc.

Recovery of the organosilylamine can be achieved by separa tion of saltsfollowed by distillation, in accordance with stan- 5 dard procedures.

Methods for making some of the halosilylorgano compounds of Formula (2)are well known, and are shown by Sveda U.S. Pat. No. 2,561,429. Forexample, a dihalosilane such as dimethyldichlorosilane can be reactedwith halogenated aromatic hydrocarbon such as pdibromobenzene employingmetallic magnesium and an hydrous ethyl ether. in addition to theGrignard reaction other organometallic reagents can be employed such asorganolithium compounds, in accordance with the method of G. Baum,

Journal of Organic Chemistry, 23, 480 (1958). There also can be utilizedaddition of silanes having hydrogen attached to silicon to aliphaticallyunsaturated radicals of various organic compounds such as diallyl ether,or the platinum catalyzed addition of a silane having hydrogen attachedto silicon to a silane having aliphatically unsaturated hydrocarbonradicals attached to silicon. Some of these methods are shown inLamoreaux U.S. Pat. No. 3,220,972 and Ashby U.S. Pat. Nos. 3,159,601 and3,159,662 which are assigned to the same as signee as the presentinvention.

There are included by the organosilylamines of Fonnula l compounds ofthe formula.

(CHs)zCHNNS iCHzCHrS:iNHCH(CH;):

551i? oH;)=cHNHsii os mrzcmom), 40 cm on,

I (FHa CIH:

( N-S iSi-N z CH; CH; (1113 (EH;

(ozHihNsilCI1CH1CH2CH21N(C2H5)Z CH; om

CH: CH;

(CH3)!NS|1 S lN(CH3)2| etc.

CH3 3H: Some of the halosilylorgano compounds of Formula 119 fi LPlcisicmcmcmsicl cisicmcmcmocmcmcmsici CH1 cm cm cm cm ms OSi-Q 2,-s1c1CH; CH. cm

lncluded by the aliphatic and heterocyclic amines which can be reactedwith the halosilylorgano compounds of Formula (2) to produce theorganosilylarnines of Formula l are for example, dimethylarnine,diethylamine, isopropylamine, n-butylarnine, methylethylamine, etc.,piperidine, pyrrolidine, and morpholine.

As shown in my copending application Ser. No. 452,933 filed May 3, 1965U.S. Pat. No. 3,305,525, which is assigned to the same assignee as thepresent invention, there is described a method for making organosiliconpolymers utilizing silylamines of the formula,

YSiR Y, (3) and YSiR (OSiQ ),,OSiR Y, (4) by contacting such materialswith certain silanol containing organosilicon materials, where R is aspreviously defined, Q is selected from R radicals and cyanoalkylradicals, and n is an integer equal to l to 1,500, inclusive.

It is also the object of the present invention to provide a method formaking organosilicon polymers by contacting silanol containing materialconsisting essentially of chemically combined diorganosiloxy units ofthe formula,

Qz with organosilylamines of Formula (1), or silylamines of the formula,

and optionally in the presence of hydroxy containing material of theformula,

Q(Q2SiO),,.H, 7 or silylamine of the formula,

R SiY, (8) to provide for the production of organosilicon polymersconsisting essentially of chemically combined Q SiO units and SiRSiO Runits, where the ratio of the sum of R and Q radicals to silicon has avalue in the range of between about 1.95 to 2.4, inclusive, where R, R,Y are as defined above, Q is selected from R radicals and cyanoalkylradicals, n is an integer equal to from 1 to 1,500, inclusive, and m isan integer equal to from 3 to 1,000, inclusive.

Included by the silanol containing organosilicon materials consistingessentially of chemically combined di-organosiloxy units of Formula (5),are silanol-terminated diorganopolysiloxanes of the formula,

where n is an integer equal to l to 1,500, inclusive.

The above silanol-terminated diorganopolysiloxane can be made bystandard hydrolysis procedures involving the hydrolysis ofdiorganodihalosilanes of the formula, Q,six,. Equilibration of cyclicpolydiorganosiloxanes, or mixtures thereof, included by the formula (QSiO),,, where Q can be for example, methyl or phenyl, and b is aninteger equal to 3 to 8, inclusive, can provide for higher molecularweight silanolterminated diorganopolysiloxanes. Controlled amounts ofwater can be added to the polymer to achieve the desired finalviscosity. silanol-terminated diorganopolysiloxanes produced by thereversion of higher molecular weight organopolysiloxanes preferably havea viscosity between 200 to 50,000 centipoises at 25 C. Included by thesilanol-terminated diorganopolysiloxanes of Formula (9) are polymersconsisting essentially of dimethylsiloxy units and copolymers ofdimethylsiloxy units with one or more members selected fromdiphenylsiloxy units, methylphenylsiloxy units, methylcyanoethylsiloxyunits, methyltrifluoropropylsiloxy units, etc. These polymers can havemajor amounts of either diphenylsiloxy units, or dimethylsiloxy units.

The silanol containing organopolysiloxanes of Formula (7) can be made byequilibrating a mixture of from 0.01 to 20 mole percent of C sio, units,and mole percent to 99.9 mole percent of Q SiO units. The silanolcontaining organopolysiloxanes of Formula 9) can contain from 0.02 to 18percent by weight of hydroxy radicals attached to silicon, based on thetotal weight of silanol-containing organopolysiloxane.

There are provided by the method of the present invention organosiliconfluids having viscosities from about 30 centipoises to as high as100,000 centipoises, or higher at 25 C, which can be silanol-terminated,or terminated with Q SiO- units or R SiO-units and consist essentiallyof chemically combined R SiO units and SiRSiO units. The employment ofsilylamine of Formula 8), or silanol containing organopolysiloxanes ofFormula (7), in combination with the organosilylamine of Formula l andsilanol containing organopolysiloxane of Formula 9), in an amountsufficient to provide for a ratio of the sum of Q and R radicals persilicon atom, having a value greater than 2, and up to about 2.4,inclusive, can provide for fluids having either terminal Q SiO units, RSiO units or a mixture of such units. In instances wheresilanol-terminated fluids are desired, mixtures of organosilylamines ofFormula (1) and silanol-terminated organopolysiloxanes of Formula (9)can be employed which are free of silylamine of Formula (8), or silanolcontaining organopolysiloxane of Formula (7), where the ratio of Yradicals of organosilylamine to silanol radicals of silanol-terminatedorganopolysiloxane has a value less than one. Room temperaturevulcanizing organosilicon compositions filled with for example, silicafiller, can be made from the aforedescribed silanol-terminatedorganosilicon fluids by employing ethylpolysilicate in combination witha metal soap catalyst as utilized in Berridge U.S. Pat. No. 2,843,555assigned to the same assignee as the present invention. Also,organoacyloxysilanes such as methyltriacetoxy silane can be employedwhich are shown in Smith et a]. U.S. Pat. No. 3,293,204, also assignedto the same assignee as the present invention.

There are also provided by the present invention, organosilicon gumswhich can be either silanol-terminated, or terminated with Q SiO units,R SiO units, or mixtures thereof. These gums can have viscositiesbetween about 500,000 centipoises to as high as 650 million centipoisesat 25 C. The employment of sufficient organosilylamine of Formula (1) incombination with silanol-terminated organopolysiloxane of Formula (9) toprovide for a ratio of Y radicals to silanol radicals having a value ofat least one, will provide for effective results. A proportion ofsufficient silylamine of Formula (8) or silanol containingorganopolysiloxane of Formula 7) should be employed in combination withorganosilylamine of Formula (1), and silanol-terminatedorganopolysiloxane of Formula (9) to provide for a ratio of the sum of Qand R radicals per silicon having a value of from greater than 2 toabout 2.001 inclusive, where polymers are desired having terminal R SiOunits, Q Sio units, or mixtures thereof.

The organosilicon polymers or gums which can be made in accordance withthe practice of the invention consist essentially of chemically combinedQ Sio and R R SiRSiO R R units, and contain less that 1 percent byweight of volatiles based on the weight of the gum. Some of the gums canbe employed in applications similar to the polymer shown by Agens U.S.Pat. No. 2,448,756, Sprung et al. US. Pat. No. 2,448,556, Marsden U.S.Pat. No. 2,521,528, etc., all assigned to the same assignee as thepresent invention. These gums can be milled with 30 to 300 parts offiller, per 100 parts of gum. Such fillers include reinforcing fillerssuch as fumed silica, as well as extending fillers, such as titaniumoxide, etc. In addition, conventional peroxide catalyst also can beincorporated. With respect to the organopolysiloxane gums made inaccordance with the practice of the present invention, those consistingessentially of chemically combined dimethylsiloxy units can havemolecular weights up to 2 million. The gums made in accordance with theinvention contain less than 1 per cent by weight of volatiles based onthe weight of the gum.

For example, some of the gums which can be made in accordance with thepractice of the invention can have the average formula such as A CH SiSi 1 a 4 1 3)? CH2 t QH: H3

ing the mixture to achieve a maximum viscosity and then removing anyunreacted material or byproduct at a reduced pressure.

In order that those skilled in the art will be better able to practicethe invention, the following examples are given by way of illustration,and not by way of limitation. All parts are be weight.

EXAMPLE 1 There were added with stirring 280 parts of isopropylamine toa solution of 263 parts of l ,4- bis(dimethylch1orosilyl)benzenedissolved in 1,700 parts of dry toluene. The isopropylamine was addeddropwise and the mixture was cooled externally with ice during theaddition. When the addition was complete, the mixture was heated to 75to 80 C for 2 hours. The amine salt was filtered off and the filtratewas distilled to yield 107.5 parts of a product having a boiling pointof 110 C at 0.2 mm. Based on its infrared spectrum, the product was1,4-bis(isopropylaminodimethylsilyl)benzene of the formula,

where v is an integer having a value of from 2 to 30, w is an integerhaving a value of from 2 to 3, and x is an integer having a value offrom 5to 50.

The process of the present invention can be practiced by mixing theorganosilylamine and the silanol containing organosilicon material at atemperature between to 200 C. Preferably temperatures between l0 to 170C can be employed. The order of addition of the various reactants is notcritical. However, in instances where monofunctional silylamine ofFormula (8) is employed in combination with the organosilylamine ofFormula (1), it is preferred to add the monofunctional silylamine priorto the organosilylamine. An amount of 0.001 to 2 parts of monofunctionalsilylamine of Formula (8), to organosilylamine of Formula (1) can beemployed.

It is preferred to practice the method of the invention undersubstantially anhydrous conditions to preclude any undue hydrolysis of Yradicals of the organosilylamine before intercondensation is achieved,with silanol containing organosilicon material. In instances wheresubstantially anhydrous conditions are employed, rapid addition ofexcess silylamine can impede further intercondensation. However, theintroduction of moisture will provide for further intercondensation bycreating further silanol due to the hydrolysis of terminal Y radicals.Experience has shown that complete intercondensation is substantiallyretarded if an organic solvent is utilized. in order to facilitatestirring however, minor amounts of an inert organic solvent such as lessthan 10 percent by weight of the reaction mixture can be introduced toreduce the viscosity of intercondensation product. For example, benzene,xylene, toluene, and the like can be used.

Excess of the organosilylamine, beyond that quantity required to effectintercondensation of silanol with silylamine radicals, such as inamounts sufficient to provide for from one to five Y radicals, persilanol radical, can provide for eflective results.

Reactions are generally most conveniently performed at atmosphericpressure conditions. However, pressures of below atmospheric can beutilized. Recovery of the desired product resulting from the contact ofthe organosilylamine with the silanol containing material can be readilyachieved by allow- Si(CHa)a EXAMPLE 2 There was added at %-hourintervals, 0.09 part of the organosilylamine of Example I, to 20 partsof a silanol-terminated dirnethypolysiloxane which was stirred andheated at 60 C. After about 1.2 part of the organosilylamine had beenadded a gum had formed having an intrinsic viscosity [1;] in toluene at25 C of 1.8 dl/g. A portion of this gum was compounded with 40 parts offumed silica and 2 percent by weight of the gum of benzoyl peroxide. A20-mil sheet was presscured at 150 C for 10 minutes. There was obtainedan elastomer having a tensile of 600 (psi) and an elongation of 250(percent).

EXAMPLE 3 There were added 49 parts of dirnethylchlorosilane to amixture of 58 parts of dimethylvinylchlorosilane and 30 parts, permillion of the resulting mixture, of a platinum catalyst shown byLamoreaux US. Pat. No. 3,220,972 while the mixture was stirred. Theaddition was performed at a temperature of 65 C. After the addition wascomplete, the mixture was heated to 120 C for 1 hour. There was obtaineda percent yield of l,2-bis(dirnethylchlorosilyhethane which solidifiedat 32 C.

There were added dropwise, 150 parts of diethylamine to a stirredsolution at 10 C of parts of the above bis(dimethylchlorosilyl)ethanedissolved in 1,000 parts of dry toluene. When the addition was complete,the mixture was heated to 1 10 C for one half hour. The amine salt wasfiltered ofi and the filtrate was distilled to yield 81 parts of productboiling at 80 C at 0.2 mm. Based on its infrared spectrum, the productwas l,2-bis(dimethy1diethylaminosilyl)ethane of the formula,

EXAMPLE 4 There was added at )-hour intervals, 0.09 part of the abovebis(dimethyldiethlaminosilyl)ethane, to 40 parts of a silanolterminatedpolydimethylsiloxane at 100 C which had a viscosity of 3,200 centipoisesat 25 C. After 0.72 part of the organosilylamine had been added, therewas obtained a gum having an intrinsic viscosity [1;] in toluene at 25 Cof 1.4 dl/g. It was compounded with 40 parts of silica filler andpresscured at 150 C for 10 minutes with 2 percent by weight of benzoylperoxide. An elastomer was obtained having a tensile (psi) of 790, andan elongation (percent) of 165 at break.

EXAMPLE 5 There were added dropwise 205 parts of dimethylchlorosilaneover a period of several hours to 98 parts of diallylether containing 30parts of the platinum catalyst of Example 3, per million parts ofdiallylether. The resulting mixture was then heated under reflux for 24hours. Distillation of the mixture yielded 85 parts of a product havinga boiling point of 107 to 1 C at 0.5 mm. The product wasbis(dimethylchlorosilylpropyl)ether whose identity was confirmed bychlorine analysis and its infrared spectrum.

There were added 85 parts of the abovebis(dimethylchlorosilylpropyl)ether to 80 parts of isopropylamine in 650parts of dry toluene cooled in an ice bath. During the addition, themixture was vigorously stirred. When the addition was complete, themixture was heated to 1 10 C for 1.5 hours. The amine salt was filteredoff and the filtrate was distilled to yield 30 parts of a product havinga boiling point of l24-l 26 C, at 0.3 mm. Based on its method ofpreparation and its infrared spectrum, the product wasbisdimethylisopropylaminosilylpropyl)ether of the formula,

(III-Ia (IJ a (CH3)2CHNHSIlCH CH;CHzO CHgCH2CHz?lNHCH(CH3)2 CHE; C113EXAMPLE 6 Increments of the bis(silylamino)ether of Example 5 were addedto 40 parts of the silanol-terminated polydimethylsiloxane of Example 4at 70 C. After 1.5 part of the amine had been added, there was obtainedafter several days, a sofi gum having an intrinsic viscosity [1 intoluene at 25 C of 0.95 dl/g.

EXAMPLE 7 In accordance with the procedure of Example 3, 55 parts ofdimethylchlorosilane were added to 65 parts of dimethylallylchlorosilaneat a temperature of 90 C in the presence of 30 parts of platinumcatalyst, per million parts of mixture. There was obtainedl,3-bis(dimethylchlorosilyl)propane; b.p. 93 C at 9 mm. Thecorresponding bis(dimethylaminodimethylsilyl )propane was prepared bythe following procedure.

There were added 55 parts of dimethylamine to 65 parts of Cl(Cl-liCl-l,Cl-l CH Si(Cl-l ),Cl in 550 parts of dry toluene at 0 C. When theaddition was completed, the mixture was heated to 1 10 C for 30 minutes.The mixture was allowed to cool. It was then filtered and the filtratewas distilled. There was obtained 33 parts of a product having theformula,

3)2 3)z z z 'b w a)g 3)z based on its method of preparation and itsvapor phase chromatograph.

A gum having an intrinsic viscosity [1 in toluene at 25 C of 1.1 dl/gwas prepared by mixing the above bis(dimethylaminosilyl)propane with thesilanol-terminated polymer of Example 6. The gum was compounded with 40parts of filler, and press-cured with 1.6 percent benzoyl peroxide inaccordance with the previously described procedure. A rubber wasobtained having 1,230 tensile (psi), and 365 (percent) elongation atbreak.

3 EXAMPLE 8 (EH CH;

A mixture of parts of the above .organosilylamine, and parts of asilanol-tenninated polydimethylsiloxane having 10.5 percent by weight OHis stirred at -l0 C under nitrogen. It is gradually heated to 60 C withstirring until no further evolution of dirnethylamine is effected. Thereis obtained a silanol-terminated fluid having a molecular weight ofabout 2,500 and consisting of chemically combined A mixture of 100 partsof the above fluid and 10 parts of methyltriacetoxysilane is blendedunder atmospheric conditions. An elastomer is obtained after 10 hoursshowing valuable insulating properties.

While the foregoing examples have been limited to only a few of the verymany organosilylamines of the present invention, it should be understoodthat the present invention is directed to a much broader class oforganosilylamines as shown by Formula (1), which can be made byeffecting contact between halosilylorgano compounds of Formula (2) andvarious aliphatic or heterocyclic amines previously described.

It also should be understood that the present invention is also directedto a method for making a much broader class of organopolysiloxanepolymers consisting essentially of chemically combined Q R R SiOunits,and SiRSiO Q R R units, which can be in the form ofsilanol-terminated fluids, or gums, or fluids or gums terminated with RSiO units, Q SiO units, or mixtures thereof.

What 1 claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A method which comprises effecting contact between (A) anorganosilylarnine, and (B) a silanol-containing organosilicon material,at a temperature of from 30 to 200 C., to provide for the production ofan adduct having a molecular weight higher than (A) or (B), where (A) isa member selected from,

R R YSiRSiY,

R R R R (b) YSiRSMOSiOHnOSiRSlY.

R R R R c. a mixture of a monofunctional silylamine of the formula, aand a member selected from (a), (b) and mixtures thereof,

and (B) is a member selected from,

H, and

a mixture of (d) and a member selected from said monofunctionalsilylamine and silanol-containing organosilicon material of the formula,

where Y is a monovalent amino radical selected from where R' is selectedfrom hydrogen and R radicals, n is an integer equal to from 1 to 1,500,inclusive, Q is selected from R radicals and cyanoalkyl radicals, in isan integer equal to from 3 to 1,000, inclusive, and the ratio of the 5sum of the R radicals and Q radicals per silicon atom, can

have a value in the range of between about 1.95 to 2.4, inelusive,

2. A method in accordance with claim 1, which provides for theproduction of an organopolysiloxane gum having a viscosity of at least500,000 centipoises at 25 C.

3. A method in accordance with claim 1, which provides for theproduction of an organopolysiloxane fluid having a viscosity between 30centipoises to 100,000 centipoises at 25

2. A method in accordance with claim 1, which provides for theproduction of an organopolysiloxane gum having a viscosity of at least500,000 centipoises at 25* C.
 3. A method in accordance with claim 1,which provides for the production of an organopolysiloxane fluid havinga viscosity between 30 centipoises to 100,000 centipoises at 25* C.